The Knowledge
🚦 Who Really Invented the Modern Traffic Light?
The modern traffic light, largely attributed to Garrett Morgan’s 1923 invention, introduced a critical yellow warning light that improved public safety. Despite his significant impact on traffic systems, Morgan’s contributions have often been overlooked due to historical racism.
Last Updated on February 14, 2026 by Daily News Staff
When you think about the traffic light, you probably picture green for go, red for stop, and maybe a frustrated glance at the yellow. But have you ever stopped to ask:Â Who actually invented this system we take for granted every day?
The story of the modern traffic light isn’t just about technology—it’s about innovation, public safety, and a Black inventor named Garrett Morgan who changed the way we move through the world.
🔦 Early Traffic Signals: A Dangerous Beginning
Before cars dominated streets, early attempts at traffic control involved manual policing and hand signals. In 1868, the first gas-powered traffic signal was installed in London outside the British Houses of Parliament. Designed by J.P. Knight, a railway engineer, this early signal exploded after just a month due to a gas leak—killing a police officer and abandoning the idea for years.
👉 Read more from History.com
As cars became more common in the early 20th century, so did traffic jams—and accidents. Cities needed a safer, more efficient solution.
🛠️ Enter Garrett Morgan
In 1923, Garrett Morgan, an African-American inventor and entrepreneur from Cleveland, Ohio, received U.S. Patent No. 1,475,024 for a traffic control device that added a crucial feature: a “warning position” between stop and go. This idea is the basis for today’s yellow light.
His signal was:
- Manually operated
- T-shaped
- Designed to be mounted on a post
- And included a buffer phase to clear intersections before switching direction
This innovation was not only about traffic flow—it was about safety and preventing collisions at a time when automobile fatalities were rapidly increasing.
Morgan sold the rights to his invention to General Electric for $40,000 (equivalent to over $700,000 today), though his contributions were overlooked for decades.
👉 View the full patent on Google Patents
⚙️ Was Morgan theÂ
Only
 Inventor?
No. Traffic signal history has multiple contributors:
- Lester Wire, a Salt Lake City policeman, created an electric traffic light prototype in 1912.
- William Ghiglieri patented an automatic signal in 1917.
- Garrett Morgan’s version stood out for its practical innovation—the transitional phase—and for being one of the first widely adopted and commercially viable versions.
In other words, Morgan helped move the traffic light from an experimental device to a nationwide safety standard.
🎥 Watch the Story in 60 Seconds
We break this story down in our latest Forgotten Genius Fridays episode from The Knowledge series on STM Daily News.
📺 Watch “Who Really Invented the Modern Traffic Light?” here: https://youtu.be/cS-emlzhjjk
✊ Why Garrett Morgan Deserves More Recognition
Garrett Morgan’s impact goes far beyond traffic lights. He also invented a gas mask used by firefighters and soldiers, and he launched one of the first Black-owned newspapers in the U.S.
He was a true innovator, working in an era where his contributions were often ignored due to racism. Today, we honor his legacy by telling his story and recognizing how his vision saved countless lives.
🧠 Now you know.
— STM Daily News
Dive into “The Knowledge,” where curiosity meets clarity. This playlist, in collaboration with STMDailyNews.com, is designed for viewers who value historical accuracy and insightful learning. Our short videos, ranging from 30 seconds to a minute and a half, make complex subjects easy to grasp in no time. Covering everything from historical events to contemporary processes and entertainment, “The Knowledge” bridges the past with the present. In a world where information is abundant yet often misused, our series aims to guide you through the noise, preserving vital knowledge and truths that shape our lives today. Perfect for curious minds eager to discover the ‘why’ and ‘how’ of everything around us. Subscribe and join in as we explore the facts that matter.  https://stmdailynews.com/the-knowledge/
